Which of the following happens when the death rates are brought down…

The correct answer is Option (3) → Population Explosion

Option (1) Demographic Transition — Incorrect. The theory of demographic transition describes the whole movement of a society through three stages of population growth, from high birth and death rates to low ones. The fall in death rates happens within it, but the name of what follows that fall is narrower.

Option (2) Demographic Dividend — Incorrect. The demographic dividend is the benefit that comes from a larger proportion of workers relative to non-workers, when the dependency ratio falls. It is about the age structure, not about death rates falling faster than birth rates.

Option (3) Population Explosion — Correct. Between the first and last stages of the demographic transition comes a transitional stage with very high rates of population growth. This ‘population explosion’ happens because death rates are brought down relatively quickly through advanced methods of disease control, public health and better nutrition, while society takes longer to change its reproductive behaviour, so birth rates stay high.

Option (4) Population growth rate — Incorrect. The growth rate is only a measure, the difference between the birth rate and the death rate. It can be high or low; it does not name what happens when death rates fall quickly.